GENERAL DESCRIPTION

The W83194R-37/-58 is a Clock Synthesizer for VIA chipset. W83194R-37 provides all clocks required for high-speed RISC or CISC microprocessor such as Intel PentiumPro, AMD or Cyrix. Eight different frequencies of CPU, W83194R-58 provides all clocks required for high-speed RISC or CISC microprocessor such as Intel PentiumII and also provides 16 different frequencies of CPU clocks by software setting (additional register0 bit2). AGP and PCI clocks are externally selectable with smooth transitions. The W83194R-37/-58 provides AGP clocks especially for clone chipset, and makes SDRAM in synchronous frequency with CPU or AGP clocks.

The W83194R-37/-58 provides I2C serial bus interface to program the registers to enable or disable each clock outputs and choose the 0.25%, 0.5% or 0.5%,1.5% center type spread spectrum to reduce EMI.

FEATURES

· Supports PentiumÔ, PentiumÔ Pro, PentiumÔ II, AMD and Cyrix CPUs with I2C.

· 4 CPU clocks

· 12 SDRAM clocks for 3 DIMs

· Two AGP clocks

· 6 PCI synchronous clocks.

· Optional single or mixed supply:

   (VDD = VDDq3 = VDDq2 = VDDq2b = 3.3V) or (VDD = VDDq3 = VDDq2 = 3.3V, VDDq2b = 2.5V)

· Skew form CPU to PCI clock -1 to 4 nS, center 2.6 nS, AGP to CPU sync. skew 0 nS (250 pS)

· SDRAM frequency synchronous to CPU or AGP clocks

· Smooth frequency switch with selections from 60 to 100 MHz CPU (-37) and 66 to 150 MHz (-58)

· I2C 2-Wire serial interface and I2C read back

· ±0.5% or ±1.5% (-37) and 0.25%, 0.5% (-58) center type spread spectrum to reduce EMI

· Programmable registers to enable/stop each output and select modes (mode as Tri-state or Normal)

· MODE pin for power Management

· 48 MHz for USB

· 24 MHz for super I/O

· Packaged in 48-pin SSOP